Using split in a hashtable

I found the following code to output some information from vCenter:

Get-VM |
Select Name,
@{N="Datastore";E={[string]::Join(',',(Get-Datastore -Id $_.DatastoreIdList | Select -ExpandProperty Name))}},
@{N="UsedSpaceGB";E={[math]::Round($_.UsedSpaceGB,1)}},
@{N="ProvisionedSpaceGB";E={[math]::Round($_.ProvisionedSpaceGB,1)}},
@{N="Guest";E=($_.Guest}},
@{N="PowerState";E={$_.PowerState}}, 
@{N="Notes";E={$_.Notes}} |
Export-Csv C:\Temp\report.csv -NoTypeInformation -UseCulture

Select allOpen in new window

The problem I am having is that the output of "Guest" returns output in the following format:

MyVirtualMachine:Microsoft Windows Server 2008 (32 bit)

What I would like is not to output the "MyVirtualMachine:" bit.  I've used the split command before to do something like this but I can't get it to work inside a hash table. Also I think I need to convert the "Guest" value to a string before I can use split.

I would appreciate advice on how to do this.  Thanks.